Method for molding terminals in workpieces



Aug. 5, 1969 I R. M. CARLSON ET AL 3,458,931

METHOD FOR MOLDING TERMINALS IN WORKPIECES Original Filed Sept. 16, 19636 Sheets-Sheet 1 INVENTORS RM CARLSON. L. P JASORKA JE MULCONREV GA.TR/MBLE ATTORNEY Aug. 5, 1969 R. M. CARLSON E A 3,458,931

METHOD FOR MOLDING TERMINALS IN WORKPIECES Original Filed Sept. 16, 19636 Sheets-Sheet 2 Aug. 5, 1969 R. M. CARLSON ET AL 3,453,931

METHOD FOR MOLDING TERMINALS IN WORKPIECES Original Filed Sept. 16, 19636 Sheets-Sheet 5 R. M.CARLSON ETAL 3,458,931

METHOD FOR MOLDING TERMINALS IN WORKP IECES Aug. 5, 1969 6 Sheets-Sheet4 Original Filed Sept. 16, 1963 Aug. 5, 1969 R. M. CARLSON ET AL3,458,931

METHOD FOR MOLDING TERMINALS IN WORKPIECES Original Filed Sept. 16, 19636 Sheets-Sheet 5 United States Patent 3,458,931 METHOD FOR MOLDINGTERMWALS IN WORKPIECES Robert M. Carlson, Ga'nanna, Larry P. Jasorka,Columbus, and John F. Mulconrey and Glenn A. Trimble, Gahanna, Ohio,assignors to Western Electric Company, Incorporated, New York, N.Y., acorporation of New York Original application Sept. 16, 1963, Ser. No.309,125, now Patent No. 3,330,019, dated July 11, 1967. Divided and thisapplication June 9, 1967, Ser. No. 652,646

Int. Cl. H011 9/00; 1323p 17/00 U.S. Cl. 29-630 4 Claims ABSTRACT OF THEDISCLGSURE Methods of molding terminals in bobbins including the stepsof threading a plurality of wires through openings formed in a first dieblock so that the ends of the wires extend from a portion of the dieblock which forms a mold cavity when joined with a second die block. Theends of the wires are enlarged slightly by coining and the first dieblock is moved toward the second die block thereby pulling the enlarged,coined ends of the wires therewith into the mold cavity formed by thejoined first and second die blocks. A plastic material is deposited intothe mold cavity and is cured therein to form the bobbin having thecoined ends of the wires embedded therein. Thereafter, the first andsecond die blocks are moved apart and intermediate portions of the wiresare cut to provide the terminals extending from the bobbin.Additionally, the ends of the wires are coined in preparation for themolding of a subsequent bobbin.

This is a division of application Ser. No. 309,125, filed Sept. 16,1963, now Patent No. 3,330,019.

This invention relates to methods of molding workpieces and particularlyto methods of molding terminals in a workpiece simultaneously with themolding of the workpiece.

In the manufacture of small coil forms of miniature electricalcomponents for electronic switching systems, difiiculty is encounteredin providing the small coil forms with terminals. In some instances thesurface into which the terminals are to be placed are only one-sixteenthof an inch wide and the terminals are manufactured from 22-gauge wire.Further, as the terminals must be accurately positioned in the coil formso as to mate with component units when assembled, it is extremelydifiicult and tedious to properly position the terminals in the coilform.

Applicant discovered that by molding terminal wire stock into the coilform simultaneously with the molding of the coil form, the diflicultiesinherent in inserting terminals into completed coil forms were avoided.Difi'iculty was encountered, however, in cutting the terminal wire stockso as to properly form the terminals in the coil form and to coin cutends of the wire stock for subsequent molding operations.

Therefore, an object of the present invention is to provide a new andimproved method of providing workpieces with terminals.

A further object of the present invention is to provide a new andimproved method of molding terminals in workpieces.

It is a further object of the invention to provide a new and improvedmethod of molding strands of terminal wire stock in a workpiecesimultaneously with the molding of the workpiece.

It is an additional object of the invention to provide 3,458,931Patented Aug. 5, 1969 a new and improved method of molding strands ofterminal wire stock in a workpiece simultaneously with the molding ofthe workpiece and for coining the terminal wire stock for subsequentmolding operations while simultaneously cutting the terminal wire stockto form terminals in the workpiece.

With these and other objects in view, the present invention contemplatesa method of molding terminals in a workpiece simultaneously with themolding of the workpiece, wherein: at least one strand of terminal wirestock is advanced with a die block as the die block is displaced to forma molding cavity with a second die block, plastic material is suppliedto the molding cavity, and heat is applied to the molding cavity to moldthe workpiece about the strands of terminal wire stock. Subsequently,the die blocks are displaced apart to release the workpiece and theterminal wire stock is cut and coined to form terminals in theworkpieces and to flatten the terminal wire stock for subsequent moldingoperations.

Other objects and advantages of the present invention will be apparentfrom the following detailed description when considered in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a partially cutaway side view of an apparatus embodying theprinciple features of the instant invention;

FIG. 2 is the same view as FIG. 1 showing an operational sequence of theapparatus;

FIG. 3 is a partial view of FIGS. 1 and 2 showing a further operationalsequence of the apparatus;

FIG. 4 is an enlarged view of a molded workpiece;

FIG. 5 is a sectional view of FIG. 2 taken along lines 5-5;

FIG. 6 is an enlarged view of a portion of a molding cavity and a wirecoining and cutting tool;

FIG. 7 is an enlarged sectional view of the terminal wire coining andcutting tool taken from FIG. 1 and showing the cutaway portions of thetool;

FIG. 8 is the same viey as FIG. 7 showing an operational sequence of thetool;

FIG. 9 is the same view as FIGS. 7 and 8 showing an additionaloperational sequence of the tool;

FIG. 10 is a partial view of FIG. 8 looking down on the tool and showingthe position of strands of terminal wire stock and of a workpiece in thetool, and

FIG. ,11 is a partial view of FIG. 9 looking down on the tool andshowing the position of strands of terminal wire stock and of aworkpiece in the tool.

As seen in FIG. 1, an apparatus for molding workpieces and forsimultaneously molding terminals therein is generally indicated by thenumeral 10. A pair of die blocks 11 and 12 are mounted on a plurality ofspaced, parallel guides 13 so as to oppose each other. The die block 11is fixedly mounted on the guides 13, and the die block 12 is slidablymounted on the guides 13. The guides 13 are slidably mounted in aplurality of spaced blocks '14, 15 and 16 and are fixedly mounted in ablock 17. A material feeding housing 18 is provided with bushings (notshown) to permit the guides 13 to move freely through the housing. Theblocks 14, 15 and 16 support the guides 13 on a frame 19 of the moldingapparatus 10 in a substantially parallel relationship.

A plunger actuator 20 is mounted on the frame 19 so as to act in adirection substantially perpendicular to the longitudinal axis of theguides 13. A plunger 21 of the actuator 20 is connected to the block 17and the die block 12 by linkages 22.

As the actuator 20 is actuated to move the plunger 21 downwardly, theblock 17 and the die block 12 are displaced toward each other. As theblock 17 is fixedly mounted on the guides 13, displacement of the block17 to the left (FIGS. 1 and 2) also displaces the guides 3 13 and thedie block 11 to the left. Thus, the die blocks 11 and 12 are displacedaway from each other when the actuator 20 displaces the plunger 21downwardly. Upon the actuator 20 displacing the plunger 21 upwardly, thedie blocks 11 and 12 will be displaced toward each other in the samemanner.

As is more clearly seen in FIG. 2, the die blocks 11 and 12 have formedtherein mating cavities 30 and 31, respectively. These cavities 30 and31 form a molding cavity when the die blocks 11 and 12 are closed (FIGS.1 and 3) wherein a workpiece 32 is molded. The die blocks 11 and 12 arealso provided with slots 33 and 34 which form an aperture 35 (FIGS. 1and 3) when the die blocks are closed.

The material feeding housing 18 is provided with a generally cylindricalbore 37 which communicates with the aperture 35 when the die blocks 11and 12 are closed. A lower end 38 of the bore 37 is tapered to mate withthe aperture 35. A passageway 39 communicates with the bore 37 and isgenerally perpendicular to the bore 37. A feeding tube 40 intercepts thepassageway 39 at an angle. A plurality of pellets 41 of thermosettingmaterial are fed successively through the feeding tube 40 and,therefore, into the passageway 39.

As seen in FIG. 1, when the die blocks 11 and 12 are closed, a push rod42, carried by the die block 11, is extended into the passageway 39 soas to prohibit the pellets 41 from dropping into the passageway 39. Whenthe die blocks 11 and 12 are open (FIG. 2), the push rod 42 is retractedso as to permit the leading pellet 41 to fall into the passageway 39.This leading pellet 41 then prohibits further pellets from falling intothe passageway 39.

A ram 43 is reciprocally mounted in the bore 37. A plunger 44 of anactuator 45, when actuated, extends or retracts the ram 43 in the bore37.

As seen in FIG. 3, with the die blocks 11 and 12 closed and one of thepellets 41 in the bore 37, the actuator 45 extends the ram 43 to advancethe pellet 41 into the molding cavity formed by the cavities 30 and 31of the die blocks 11 and 12.

As is best seen in FIGS. 4 and 5, the ram 43 is provided with a dovetailslot 46, and a core rod 47 is extended into the molding cavity. Whenheat is applied to the thermosetting material of the pellet 41, theworkpiece 32 is molded into the dovetail slot 46 and about the core rod47. Thus, the ram 43 and the core rod 47 support the workpiece 32 forsubsequent operations when the die blocks 11 and 12 are opened.

As will be more readily seen in FIG. 5, the die block 12 is providedwith a slot 50. The slot 50 forms an aperture when the die blocks 11 and12 are closed which aperture permits a core housing 52 and the core rod47 to extend into the molding cavity. The core rod 47 forms an aperturein the workpiece 32 for the subsequent insertion of a coil core when theworkpiece is utilized as a coil form. The core rod housing 52 also formsa portion of the molding cavity.

As best seen in FIGS. 2 and 6, a plurality of strands 60 of terminalwire stock extends through the die block 11. Thus, upon the workpiece 32being molded in the cavity formed by the die blocks 11 and 12, the endsof the strands 60 of the terminal wire stock are also molded into theworkpiece 32. As seen in FIG. 6, by properly positioning a plurality ofapertures 53 formed in the die block 11, the strands 60 of the terminalwire stock are properly positioned in the molding cavity; and thestrands of terminal wire stock are, thus, molded in the workpiece 32 intheir predetermined terminal positions.

The die blocks 11 and 12 are provided with heating elements '54 and 55,respectively, and the core rod housing 52 is provided with heatingelements 56. The ram 43 is also heated by a heating element 57. Thus, bysupplying current to the heating elements 54, 55, 56 and 57 in anyconventional manner, the thermosetting ma- .4 terial is molded into theworkpiece 32 in the molding cavity.

Rs shown in FIG. 1, a cutting and coining tool is generally indicated bythe numeral 61. A sleeve 62 of the tool 61 is fixedly mounted to theframe 19 of the molding apparatus 10.

Referring to FIG. 7, a second sleeve 63 is carried by a plunger 64 of ahydraulic cylinder actuator 65 (FIG. 1) so as to be axially displaceablewithin the sleeve 62. Fingers or wire-forming elements 66, 67 and 68 areretained in the sleeves 62 and 63 by a plurality of pins 69. The pins 69extend into a corresponding plurality of slots 70 of the sleeve 62 and acorresponding plurality of slots 71 of the sleeve 63.

A disc 72 is spring biased by a plurality of springs 73 away from theplunger 64 so as to constantly maintain tension on the fingers 66, 67and 68 to urge the pins 69 against the top of the slots 71 in the sleeve63. When the plunger 64 is retracted, as seen in FIGS. 1 and 3, the tool61 is positioned as shown in FIG. 7. In this position the pins 69 arenear the bottom of the slots 70 of the sleeve 62 and at the top of theslots 71 of the sleeve 63.

As the actuator 65 is actuated to extend the plunger 64, the sleeve 63is displaced upwardly with the plunger 64. The fingers 66, 6'7 and 68 inresponse to the urgings of the springs 73 .are also displaced upwardlywith the sleeve 63 until the pins 69 reach the top of the slots 70 inthe sleeve 62. FIGS. 6 and 8 show the tool 61 in this position.

Further displacement of the plunger 64 displaces the sleeve 63 relativeto the sleeve 62 and the fingers 66, 67 and 68, as seen in FIG. 9. Asthe pins 69 are at the top of the slots 70, further displacement of theplunger 64 does not continue to displace the fingers 66, 67 and 68 butcompresses the springs 73. The fingers 66 and 68 are provided withcamming surfaces 74. The sleeve 63 has a tapered portion 75 whichcooperates with the camming surfaces 74 of the fingers 66 and 68. Thus,upon further displacement of the sleeve 63, as shown in FIG. 9, thefingers 66, 67 and 68 will be forced together. The travel of the sleeve63 is limited by a stop 76 on the plunger 64 striking the frame 19.

As the tool 61 is extended to the position shown in FIG. 8, the fingers66, 67 and 68 are advanced to position the strands 60 of terminal wirestock between the fingers (FIGS. 6 and 10). Upon further displacement ofthe plunger 64 to the position shown in FIG. 9, the fingers 66, 67 and68 are closed, as shown in FIG. 11, to cut the ends of the strands 60 ofterminal wire stock molded into the workpiece 32 from the terminal wirestock thereby forming a plurality of terminals 77 in the moldedworkpiece 32.

In the position shown in FIGS. 9 and 11, the ends of the strands 60 arecoined or flattened between the fingers 66, 67 and 68. Shearing surfaces78 of the fingers 66, 67 and 68 cut or shear the terminals 77 from theterminal wire stock strands 60, and coining surfaces 79 of the fingersflatten ends 80 of the terminal wire stock strands 60. The coiningsurfaces 79 are also provided with serrations 81 which burr theflattened ends 80 for better retention in the subsequently moldedworkpiece 32.

As seen in FIGS. 7, 8 and 9, the spring 82 urges the fingers 66, 67 and68 away from one another when the plunger 64 and the sleeve 63 areretracted by the hydraulic cylinder actuator 65. The sleeve 63 isfixedly mounted on the plunger 64 so as to be directly responsive todisplacement of the plunger 64.

A block 85 is fixedly mounted on the end of .a pair of spaced shafts 86'(FIGS. 1, 2 and 5) and is spring biased by compression springs 87toward the die block 11. The shafts 86 are provided with stops 88 whichupon striking butt plates 89 of the block 16 restrict furtherdisplacement of the block 85 toward the die block 11.

An ejector rod 90 is carried by the block 85 and extends into apassageway 91 of the die block 11. As the die blocks 11 and 12 areopened, i.e., displaced .away from each other, the ejector rod 90 isextended into the cavity 30 of the die block 11 so as to eject theworkpiece 32 from the die block.

Referring to FIGS. 4 and 6, the die block 11 is provided with slots 92through which the thermosetting material flows into the molding cavityfrom the aperture 35. The die block 12 is provided with similar slotswhich mate with the slots 92. Cull portions 93 of the workpiece 32 aremolded in the slots 92. A coin-like cull portion 94 is molded in theaperture 35 below the ram 43. The cull portions 93 and 94 facilitatesubsequent handling of the workpieces 32. On the finished workpiece 32the cull portions 93 and 94 are broken away from the workpiece.

As seen in FIGS. 4 and 5, the core rod 45 and the ram 43 support themolded workpiece 32 after the workpiece is ejected from the die blocks11 and 12. After the coining and shearing operation, an actuator 95withdraws the core rod 47 from the workpiece 32 and the actuator 45retracts the ram 43 to permit the workpiece 32 to drop from the moldingapparatus 10. The core rod housing 52 strips the workpiece 32 from thecore rod 47 .as the core rod is retracted by the actuator 95. The slot33 is provided with recessed portions 96 which mate with similarrecessed portions in the slot 34 and wherein projecting pin-likeportions 97 of the coin-like cull portion 94 are molded. Upon the ram 43being retracted, the pin-like portions 97 strike the material feedinghousing 18 and strip the workpiece 32 from the ram 43.

As the die blocks 11 and 12 are closed, i.e., are displaced towards eachother until they meet, the die block 11 advances relative to the strands60 of the terminal wire stock until the apertures 53 of the die block 11meet the coined or flattened portion 80 of the strands 60. Furthermovement of the die block 11 towards the die block 12 advances thestrands 60 with the die block 11 so as to position the strands 60 in thecavity 30 in the proper terminal positions for subsequent molding ofanother workpiece 32 in the die.

In operation Starting the sequence with FIG. 1, wherein a workpiece 32has been molded in the die, the first step is to actuate the actuator 20to displace the plunger 21 downwardly to open the die blocks 11 and 12.In this position the leading pellet 41 in the feeding tube 40 will dropinto the passageway 39 as the push rod 42 is withdrawn from thepassageway 39 by the displacement of the die block 11. The ejector rod90 is also advanced into the cavity 30 of the die block 11 to eject theworkpiece 32.

The actuator 65 is then actuated to extend the tool 61. The moldingapparatus will at this point assume the position shown in FIG. 2. Uponthe plunger 64 being displaced to the end of its travel by the actuator65, the tool 61 will cut and coin the strands 60 of the terminal wirestock, as shown in FIGS. 9 and 11.

At this point, the actuator 65 is actuated to retract the tool 61, theactuator 45 is actuator 45 is actuated to retracted the core rod 47 andthe actuator is actuated to retract the ram 43 thereby ejecting theworkpiece 32 from the molding apparatus 10.

The actuator 20 is then actuated to extend the plunger 21 so as to closethe die blocks 11 and 12 and advance the pellet 41 in the passageway 39into the bore 37, and the core rod 47 is extended into the die byactuator 95. The molding apparatus 10 thus assumes the position shown inFIG. 3.

The actuator 65 is actuated at this point to advance the ram 43 in thebore 37 so as to advance the pellet 41 into the molding cavity. Heat isapplied to the thermosetting material by heating elements 54, 55, 56 and57 so as to mold a workpiece 32 in the molding cavity.

The molding apparatus 10 thus has assumed the position set forth in FIG.1, and the sequence of operation is repeated to eject the formedworkpiece 32 and to form a subsequent workpiece. In setting up themolding apparatus 10 for operation, it is necessary, as will be obviousto one skilled in the art, to first coin the ends of the strands 60 ofthe terminal wire stock after the strands are inserted through the dieblock 11.

Any conventional source of power and switching arrangement may beutilized to supply current to the heating elements 54, 55, 56 and 57 forheating the thermosetting material. Further, any conventional facilitymay be utilized for displacing the plungers 21, 44 and 64 and fordisplacing the core rod 47. For example, solenoids, air cylinders orhydraulic cylinders could be used advantageously. As will be obvious toanyone skilled in the art, any conventional means can be employed toactuate the actuators 20, 45, 65 and depending upon which particulartype of actuator is used.

It is also contemplated that an air blast can be used to blow theworkpiece 32 from the molding apparatus 10 into a chute (not shown) asthe workpiece is released from the ram 43 to exhaust the workpiece fromthe molding apparatus. Passage of the workpiece 32 through the chute canbe sensed and utilized to start a new sequence of operation, therebymaking the apparatus automatic.

Futher, it would be within the scope of the invention to direct terminalwire stock into the molding cavities through both of the die blocks 11and 12 where it is desirable to mold a workpiece having terminals on twosides.

It will be understood that the above-described arrangement is merelyillustrative of the principles of the invention and many othermodifications of the invention may be made without departing from thespirit and scope thereof.

What is claimed is:

1. A method of molding strands of terminal wire stock in a workpiece,comprising the steps of:

placing the strands of the terminal wire stock through apertures of afirst die block so that ends of the strands extend from a molding-cavityside of the die block,

coining the ends of the strands of the terminal wire stock extendingfrom the apertures in the first die block to a size larger than thediameter of the apertures,

displacing said first die block relative to a second die block to bringthe die blocks together to form a molding cavity, the first die blockengaging the coined ends of the strands of the terminal wire stock andadvancing the strands into the molding cavity as the die blocks areclosed,

feeding a predetermined amount of thermosetting material into themolding cavity, and

applying heat to the molding cavity to mold the thermosetting materialabout the strands of the terminal wire stock.

2. A method of molding terminals in a workpiece, comprising the stepsof:

placing strands of terminal wire stock through apertures of a first dieblock so that ends of the strands extend from a molding-cavity side ofthe die block,

coining the ends of the strands of the terminal wire stock extendingfrom the apertures in the first die block to a size larger than thediameter of the apertures,

displacing the first die block relative to a second die block to bringthe die blocks together to form a molding cavity, the first die blockengaging the coined ends of the strands of the terminal wire stock andadvancing the strands into the molding cavity as the die blocks areclosed,

feeding a predetermined amount of thermosetting material into themolding cavity,

applying heat to the molding cavity to mold the thermosetting materialinto a workpiece about the strands of the terminal wire stock, and

cutting the ends of the strands of the terminal wire stock which aremolded in the molded workpiece to form terminals therein.

3. A method of successively forming terminals containing workpieceswherein a plurality of strands of terminal wire stock extends throughapertures in and from a molding-cavity side of a first die block and aremolded in the successively formed workpieces, comprising in seriatim thesteps of:

cutting portions of the strands of the terminal wire stock between themolding-cavity side of the first die block and a molded workpiece toform the workpiece having terminals molded therein and extendingtherefrom, the remaining end portions of the strands of the terminalwire stock extending from the molding-cavity side of the first dieblock,

coining the cut remaining ends of the strands of the terminal wire stockextending from the first die block to a size larger than the aperturesin the first die block,

displacing the first die block relative to a second die block to bringthe die blocks together to form a molding cavity, the first die blockengaging the coined ends of the strands of the terminal wire stock andadvancing the strands into the molding cavity,

feeding a predetermined amount of hardenable resinous material into themolding cavity, and

hardening said resinous material about the coined ends of the strands ofthe terminal wire stock to mold a workpiece.

4. A method of forming a molded plastic piece part having at least oneelongated member of dissimilar material extending therefrom, comprisingthe steps of:

placing at least one elongated member of dissimilar material in alaterally enclosed passage of a seg ment of a mold,

deforming a portion of the elongated member extending through thelaterally enclosed passage in the segment of the mold,

causing relative movement between the segment of the mold through whichthe elongated member extends and at least one other segment of the moldto form a mold cavity and to contemperaneously move the deformed portionof the elongated member into the mold cavity,

feeding a plastic material into the molding cavity to form a moldedplastic piece part having the deformed portion of the elongated membermolded therein, and

removing the molded piece part with the elongated member extendingtherefrom from the mold cavity by causing relative movement of thesegments of the mold longitudinally of the axis of the mold.

References Cited UNITED STATES PATENTS 3,149,375 9/1964 Gehl 18-36 XR3,209,409 10/ 1965 Grathwohl 1836 3,330,004- 7/1967 Cloyd et a1 18-362,900,662 8/ 1959 Scherry. 3,133,981 5/1964 Seele 264-261 JOHN F.CAMPBELL, Primary Examiner ROBERT W. CHURCH, Assistant Examiner US. Cl.X.R.

